TR-08The TR-TSY-000008 BellcoreTM standard (commonly referred to as TR-08) describes the generic requirements for interfacing between local digital switches and remote digital terminals via the SLC 96TM digital loop carrier system.
TR-08 has three operational modes (ICX-250 supports mode I):•Modes I & III are non-concentrated and provide unique mapping between channel numbers and DS1 time slots.
•Mode II is concentrated and there are no pre-determined relationships between the channels and timeslots. This allocation of channels to time slots is made possible by the exchange of messages between the Local Digital Switch (LDS) and remote terminal (RT).
Although commonly referred to as the TR-08 standard, the RT channel numbering scheme supported by the ICX-250 unit is described in section 9.9 of the Bellcore publication TR-TSY-000057.
The ICX-250 provides SLC-96 Frame Format and Data Link.When a T1 port is configured for TR-08 format, the voice channels assigned to this port are identified by “channel number” (according to the TR-TSY-000008 document), which may be different from the T1 time slot number. The ICX-250 supports only Group A. The relation between a channel number and corresponding slot number for TR-08 is shown in the following table.
Channel Numbers | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 |
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Time Slots | 1 | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 17 | 19 | 21 | 23 | 2 | 4 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 22 | 24 |
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ADCP-62-023 | Issue 1, September 1998 |
| © 1998, ADC Telecommunications, Inc. |